- Women account for nearly 60% of adults with HIV in
sub-Saharan Africa despite
advances in preventing HIV
- Vaginal rings are flexible products
that fit high up inside the vagina and are easy to use and handle
- The consistent use of a vaginal ring impregnated with the antiretroviral (ARV) drug
dapivirine for a month at a time reduced the risk
of HIV infection in women
- Dapivirine binds to and disables HIV's reverse
transcriptase enzyme, a key protein needed for HIV replication.
The sub-Saharan Africa contributes to the global HIV and AIDS epidemic to a large extent, with women accounting for nearly 60% of cases. In the year 2013 in this region, there were an estimated 24.7 million people living with HIV with around 1.5 million new HIV infections and 1.1 million AIDS-related deaths. While majority of the new HIV infections in sub-Saharan Africa occur in adults
over 25 years of age, young women aged 15-24 years are commonly affected.
ASPIRE (A Study to Prevent Infection with a Ring for Extended use), or Microbicide Trials Network (MTN-020), was a Phase III trial that involved 2,629 women aged 18-45 years from the African countries of Malawi, Uganda, South Africa and Zimbabwe. The study evaluated the efficacy of a medicated vaginal ring in the prevention of HIV. Vaginal rings are flexible rings that are fitted high up in the vagina by the women themselves. Medicated rings release a medication over a prolonged duration. The ring tested in the ASPIRE study contained 25 mg of the anti-HIV drug dapivirine, about 4 mg of which gets released over 28 days. Dapivirine, also known as TMC-120, belongs to a class of drugs called non-nucleoside reverse transcriptase inhibitors (NNRTIs). Drugs from this group disable HIV's reverse transcriptase enzyme, a key protein needed for HIV replication. The ASPIRE study concluded that the ring reduces the risk of HIV infection
‘Vaginal rings containing the antiretroviral (ARV) drug dapivirine have shown to reduce the risk of HIV infection if used consistently for one month at a time. These devices are easy to handle and women can insert or remove them themselves.’
An additional exploratory
analysis on the ASPIRE study by Dr.
Elizabeth R. Brown, the principal investigator of the Statistical and Data
Management Center of the NIH-funded Microbicide Trials Network (MTN) has shown
that the consistent use of the vaginal
ring for a month at a time is far more effective - it reduced the
risk of HIV infection in women by at least 56% and in some by 75% or more. Nearly 2,400 of the more than 2,600 women who
participated in the ASPIRE study were included in the analysis. Adherence was defined using residual
drug levels in the rings upon discarding. Moderate adherence was
associated with a risk reduction of HIV infection of at least 56%. - while high adherence was
associated with a risk reduction of potentially 75% or higher. Low adherence,
on the other hand, did not provide statistically significant protection from
This finding is being
reported at the 21st International Conference On AIDS in Durban, South Africa. The ASPIRE results were published online in the New England Journal of Medicine
to HIV prevention strategies is not always perfect, and we knew that not all
women used the ring consistently, so we developed an analysis to explore the
degree of HIV protection that was associated with more consistent use,"
stated Dr. Brown "Across all analyses we saw high adherence
was associated with significantly better HIV protection." Dr. Brown added.
findings from the ASPIRE study told us how much protection the dapivirine ring
afforded the study population as a whole, which included women who used the
ring often, sometimes, or not at all," explained NIAID Director Anthony S.
Fauci. "However, we know that HIV prevention tools work only if people use
them. The findings of the exploratory analysis reported today give credence to
the hypothesis that greater adherence to the dapivirine ring translates into a
higher level of protection. The HOPE trial will provide additional data that
either reinforce or refute this hypothesis," he added.
clinical trial called HOPE (HIV Open-Label Extension) or MTN-025, will
be build on ASPIRE study. Women eligible for this study will be those who have participated in
the ASPIRE study earlier and have not contracted the HIV virus. All the women
who enroll will be offered the ring. In the initial three months, the women
will receive the ring on a monthly basis. Following this period, they will be
offered three rings at a time on every quarterly visit, which is more likely to
be the case in a real-world setting. The study period will last for one year.
The choice to use the vaginal ring or
not, however, will be the woman's. This would reflect the women's acceptance of
the ring. Adherence
to the ring will be determined by measuring residual levels of dapivirine in
returned rings and blood levels of dapivirine. Women will be able to stay in HOPE for about a year after
they enroll regardless
of whether they accept or use new rings. The HOPE study will gather
additional information on the ring's safety and how women use the ring.
HOPE study will give us the opportunity to learn why women do or do not like to
use the dapivirine ring- information that might help us plan the optimal
approaches for its delivery outside of research settings, improve upon the
product and clarify how different HIV prevention options fit into women's
lives," said Dr. Jared Baeten.
ASPIRE study was led by Dr. Jared Baeten, from the University of Washington in
Seattle, and Dr.Thesla Palanee-Phillips, from the Wits Reproductive Health and HIV Institute in
Johannesburg, South Africa. They will also lead the HOPE study together with
Dr. Nyaradzo M. Mgodi, from the University of Zimbabwe-University of California San Francisco in Harare.
- Vaginal ring may cut HIV infection risk if used consistently - (http://www.eurekalert.org/pub_releases/2016-07/nioa-vr071716.php)
- HIV and AIDS in sub-Saharan Africa - (https://www.avert.org/professionals/hiv-around-world/sub-saharan-africa)